Current-transmitting devices for the axles of electric railway vehicles

ABSTRACT

A current-transmitting device interposed between the frame of an electric railway vehicle and an axle comprises a nonrotating member and a rotating member resiliently urged against the nonrotating member so as to form therewith a rotating contact unit. The said unit is carried by the frame in front of one of the ends of the axle and the rotating member is mechanically coupled with the axle end by a universal coupling so as to rotate in unison therewith in spite of the various displacements of the axle with respect to the frame. A flexible conductor forms a deformable electric connection between the rotating member and the axle end.

United States Patent [72] Inventor Louis Cabaussel Villeurbanne, France[2]] Appl. No. 865,558 [22] Filed Oct. 13,1969 [45] Patented Sept. 28,1971 [73] Assignee Societe Lucien Ferraz & cie" Rhone, France [54]CURRENT-TRANSMITTING DEVICES FOR THE AXLES 0F ELECTRIC RAILWAY VEHICLES7 Claims, 8 Drawing Figs.

[52] US. Cl 339/3 [51] Int. Cl H0lr 39/64 [50] Field of Search 339/3,5,8, 7, 9; 105/53, 54

[5 6] References Cited UNITED STATES PATENTS 1,244,533 lO/l9l7 Morse339/7X Primary ExaminerRichard E. Moore AttorneyAlexander & Dowel]ABSTRACT: A current-transmitting device interposed between the frame ofan electric railway vehicle and an axle comprises a nonrotating memberand a rotating member resiliently urged against the nonrotating memberso as to form therewith a rotating contact unit. The said unit iscarried by the frame in front of one of the ends of the axle and therotating member is mechanically coupled with the axle end by a universalcoupling so as to rotate in unison therewith in spite of the variousdisplacements of the axle with respect to the frame. A flexibleconductor forms a deformable electric connection between the rotatingmember and the axle end.

PATENTED 82928 I971 SHEET 2 OF 2 INVENTOR.

CURRENT-TRANSMITTING DEVICES FOR THE AXLES F ELECTRIC RAILWAY VEHICLESThis invenu'on relates to current transmitting devices mounted inelectric railway vehicles, between the frame and the axles, in orderthat electric current may directly flow from the frame to the wheelswithout having to pass through the axle bearings.

The role of these devices is extremely important in highpowerlocomotives since otherwise the axle bearings would be rapidlydestroyed. But of course the said devices should operate satisfactorilyin spite of the relative displacements of the axles with respect to theframe. Moreover these devices generally comprise a rotating contactmechanism including at least one brush resiliently applied against arotating surface and of course this brush should wear uniformly in suchmanner that the whole contacting area between the brush and the rotatingsurface may be maintained during the whole useful life of the brush.

In railways vehicles comprising axle boxes disposed at the ends of theaxles, each nonrotating axle box follows the verti cal displacements ofthe corresponding axle and also its angular displacements about an axislongitudinal with respect to the track (when one wheel rises more thanthe other with respect to the frame). The relative displacements to betaken into account are thus limited to the to-and-fro motion of the axlealong its own axis (i.e., transversely with respect to the track). It istherefore relatively easy, at least at moderate speeds, to providecurrent transmitting devices in which a brush is always uniformlyapplied against a flat rotating contact member (end face of the axle orcontacting plate secured thereto). But when the axle boxes or bearingsare mounted between the wheels, the current-transmitting devices arecarried by supports fixed to the frame and therefore they must take intoaccount all the kinds of movements of the axle relatively to the frame.Under such conditions with the known arrangements the brushes do notbear uniformly against the rotating contact member. The wear of theircontacting end is therefore irregular, this end is no more flat but moreor less rounded and the contacting area becomes considerably reduced,whereby the ohmic resistance to the passage of electric current isincreased and the undesirable eddy currents which flow through the axlebearings become quite noticeable.

It is the principal object of the present invention to provide acurrent-transmitting device adapted to be disposed between the frame andan axle in a railway vehicle, which will be substantially unaffected bythe relative displacements of the axle with respect to the frame.

In accordance with the present invention, in a current transmittingdevice adapted for current transmission between the frame and an axle inan electric railway vehicle, of the kind comprising a nonrotating memberand a rotating member resiliently urged against each other so as to forma rotating contact mechanism, the rotating contact mechanism is whollycarried by the frame, its rotating member being mechanically coupledwith the adjacent end of the axle by a universal coupling so as torotate in unisontherewith, and being electrically connected with thesaid axle by a flexible conductor. In the accompanying drawings:

FIG. 1 is a general vertical section of a current transmitting deviceaccording to the invention.

FIG. 2 is a small scale front view of the horseshoe-shaped supportingflange adapted to support the rotating contact mechanism of the device.

FIG. 3 is a perspective view of the slotted plate secured onto the axleend.

FIG. 4 is a fragmental perspective view of the flat flexible conductorinterposed between the rotating member of the rotating contact mechanismand the slotted plate, the said view showing the end of the conductoradapted to be secured to the crank arm of the universal coupling.

FIG. 5 is a perspective view of the portion of this braided conductorwhich comprises a ring adapted to be fixed to the said rotating member.

FIG. 6 is a small scale view showing how the current transmitting devicemay be removed from the frame.

FIGS. 7 and 8 are axial sections illustrating two modified embodimentsof the invention.

In FIG. 1 reference numeral 1 designates a side member forming part of arailway vehicle frame. This side member is in the form of a hollow beamand it comprises in front of each axle, such as 2, an open-endedhorizontal sleeve 3 which forms a tubular stay between the walls or websof the said member, while permitting free access to the adjacent end ofthe axle 2. This axle 2 is rotatably mounted in suitable bearings oraxle boxes disposed between the wheels carried by the axle, the saidwheels and the said bearings being not illustrated in the drawing. Theaxle bearings are connected with the frame by suspension springs in theconventional manner and therefore the axle may move with respect to theframe in a vertical direction, in a direction transverse to the track,and also angularly about an axis longitudinal to the track, when thevertical displacements of the wheels are unequal.

In the embodiment illustrated in Fig. 1, an inner annular supportingflange 4 is welded in sleeve 3, near the outer end thereof. This flangeis somewhat in the shape of a downwardly opening horseshoe as shown inFig. 2 with a circular outer edge and a substantially square inner edge.Three screwthreaded holes 4a provided in the said flange receive screws5 (FIG. 1) which clamp against the outer side of flange 4 another flange6, of annular shape to the inner edge of which is welded the outer end(i.e. the end remote from axle 2) of a hollow cylindrical body 7. Thisouter end is closed by a circular plate or cover 8 secured to the outerside of flange 6 by means of screws 9. Cover 8 is formed with a centralcylindrical boss 10 which extends inwardly within the hollow body 7,this boss having a square axial bore 10a which slidably receives a rod11 of complementary square cross section. The inner end of this rod 11is integral with a circular plate 12 which carries a brush 13, made forinstance of a mixture of carbon and metallic salts or metal particles. Acompression spring 14 is disposed around boss 10 between cover 8 andplate 12. The other end of rod 11 receives the terminal eyelet or plug15 of a flat braided conductor 16 connected with an appropriate point(not illustrated) of the vehicle frame.

An annular cup-shaped cap 17 is screwed onto the inner end of the hollowcylindrical body 7, the outer race of an antifriction bearing 18 (as forinstance a ball bearing) being clamped between the bottom of cap 17 andthe annular end face of body 7, as shown. The inner race of this bearingreceives a short shaft 19 on which it is maintained between a shoulder19a and a split washer 20 inserted into an appropriate groove of theshaft. The end of shaft 19 which faces brush 13 is integral with acircular contacting plate 21 against which the said brush is applied bythe reaction of spring 14. The other end of shaft 19 extends slightlybeyond bearing 20 and cap 17, and it carries the hub portion 220 of acrank am 22, the said portion being secured to the shaft by means of anaxial screw 23 and of a system of grooves and ribs which prevent anyangular displacement of arm 22 with respect to shaft 19. Arm 22 carriesan inwardly extending crankpin 24 which supports a freely rotatableroller 25. As illustrated this crankpin 24 has a screw-threaded tailportion 244 which extends through arm 22, its screw-threaded protrudingend receiving a securing nut 26. As to roller 25, it may be supported onpin 24 in any appropriate manner, as for instance by means of a ballbearing retained in position by a split washer 27, the outer race ofthis ball bearing fonning directly the rim of the roller.

The hub portion 220 is also integral with another arm 22b diametricallyopposed to the crank arm 22 and which may be considered as an extensionof the latter beyond the said hub portion 22a A driving plate 28 ismounted against the end face of axle 2 by means of screws 29. As clearlyshown in Fig. 3 the outer side of this plate (i.e. the side thereofwhich is not applied against the end of axle 2) is formed with a pair ofparallel ribs 28a between which plate 28 is slotted and these ribsextend beyond the central portion of the plate in the form of ribs 28bof smaller height between which the plate is unslotted. Roller 25disposed between ribs 28a in such manner as to form an angularconnection between plate 28 and crank arm 22. One 30 of the ends of aflat braided conductor 31 is disposed between the lower ribs 28b of theplate 28 where it is clamped against the latter by means of screws 31.This conductor extends radially between ribs 28b and it is thereafterfolded at 180 in order to extend on arm 22b on hub portion 22a and oncrank arm 22 itself, its end being soldered to a U-shaped connectingmember or plug 33 (see Fig. 4) which overlaps arm 22 to which it issecured by means of a transverse bolt 34 (FIG. 1). A flat sleeve 35(Figs. 1 and 5) is soldered on conductor 31 in the zone thereof adjacentto the end of arm 22b and this sleeve is integral with a laterallyprotruding ring 36 adapted to be threaded on arm 22b (FIG. 1).

When the axle 2 rotates, plate 28, crankpin 24 and crank arm 22 form auniversal coupling between axle 2 and shaft 19 of the rotating contactmechanism 2l-l3-1 1-14. Shaft 19 therefore rotates in unison with axle2, while brush l3, resiliently applied against the contacting plate 21,is prevented from rotating by rod 11 which is angularly retained withinbore a owing to its square cross section. The electric current flowsfrom the frame to the axle through conductor 16, rod 11, plate 12, brush13, contacting plate 21, shaft 19, hub portion 22a crank arm 22,conductor 31 and plate 28. The nonrotating brush 13 and the rotatingcontacting plate are always coaxial since the plate carrying shaft 19 iscentered by the antifriction bearing 18 with respect to the hollow body7 which carries outer cover 8 with its cylindrical boss 10 wherein thebrush-carrying rod 11 is slidably retained. The transmission of theelectric current between the frame and the axle is thus always perfectlyrealized whatever may be the relative displacements of the axle withrespect to the frame, crank am 22, roller 25 and plate 28 forming auniversal coupling. More particularly, even if spring 14 is relativelylight, the axle displacements in a transverse direction with respect tothe track have no influence whatever on the contacting surfaces even athigh speeds for which the corresponding transverse accelerations of theaxle may be considerable. Furthermore the brush wears uniformly in spiteof the angular movements of the axle about an axis longitudinal to thetrack.

When it is desired to have free access to the brush, it is sufficient toremove screws 9 and to pull cover 8 which carries boss 10 together withthe longitudinally movable unit 11-12-1 3 (the rotatably movable unit21-1922 being still carried by hearing 18, cap 17 and body 7).

In order to have access to the rotatably movable unit 2119-22 (moreparticularly to hearing 18 or to conductor 31), screws 5 are firstremoved and the said unit is pulled outwardly until conductor 31 is tautbetween terminal 30 and sleeve 35. The unit may then be tilted upwardlyas indicated by the arrow in Fig. 6. It is to be noted that owing to theopen lower end of flange 4 (see FIG. 2), it is always possible to bringarms 22 and 22b to such a position that they may pass through the saidflange. The transverse bolt 34 may then be removed and the retainingring 36 may be disengaged from arm 22b. The hollow body 7 is thus fullyliberated together with the parts which it carries. The remountingoperation is effected in the reverse order, i.e. by threading ring 36 onarm 22b, mounting bolt 34, reintroducing body 7 into sleeve 3,orientating arm 22 in such manner that roller 25 may be inserted intothe slideway formed by ribs 28a of plate 28, and finally mounting screws5.

It may be remarked that the end of conductor 31 opposed to axle 2 couldbe directly secured to arm 22b, but of course in such a manner that itmay be easily liberated at the position of Fig. 6.

In the embodiment of FIG. 7 the removable flange 6 is integral with arelatively thick hollow body 37 having two successive bore portions ofdifferent diameters. An annular brush 13 is engaged into the outerportion of the bore of body 37, i.e.

in the portion thereof which opens outwardly with respect to the vehicleframe, where it is angularly retained by means of a pin 38, while theouter race of a ball bearing 39 is mounted in the inner portion, ofsmaller diameter, of the said bore, between a central shoulder and asplit ring 40 inserted into an appropriate annular groove of the bore. Ashaft 41 is mounted with relatively slight friction in the inner race ofthis ball bearing 39. This shaft 41 extends through the central bore ofbrush 13 and its outer end is formed with a contacting plate 42 whichbears against the said brush 13. The inner end of shaft 41 has a centrallug 41a to which is attached one end of a traction spring 43. Screws 44clamp against the end of axle 2 a plate 45 having a central 45a to whichthe other end of spring 43 is attached. Braided conductors 46 connectelectrically plate 45 and shaft 41 with each other.

It will be understood that spring 43 maintains plate 42 applied againstbrush 13 in spite of the relative displacements of axle 2, whilesimultaneously forming a resilient universal coupling owing to whichshaft 41 rotates in unison with the said axle. Here again current istransmitted without any noticeable ohmic resistance between the frameand the axle. The tenninal eyelet 15 (Fig. 1) of conductor 16 may befixed to any appropriate point of the device, as for instance under thehead of one of screws 5.

Fig. 8 shows a modification of the embodiment of FIG. 7, wherein thespring operates by compression. The annular brush 13 is secured in anyappropriate manner to the inner side of the cover 6 of the device. Thiscover is here formed with an inwardly directed gudgeon 47 of thecircular cross section, on which is rotatably mounted the hub 48 of acontacting plate 49. In FIG. 8 hub 48 is directly carried by pin 47 butit could also be supported by the outer race of a ball bearing or thelike the inner race of which would be mounted with slight friction onthe said pin. The compression spring 50 extends between plate 49 andanother plate 51 fixed against the end of axle 2 by means of screws 52.The ends of spring 50 are bent at right angles and are inserted intoholes provided in plates 49 and 51 in order that the said spring mayplay the role of a resilient universal coupling between the contactingplate 51 and axle 2. A tubular braided conductor 53 forms alow-resistance electric connection between hub 48 and a central bossprovided on plate 51 for centering the corresponding end of spring 50.Here again the terminal eyelet or plug 15 of conductor 16 may be clampedunder the head of a screw 5.

It is obvious that in the rotating contact device formed by the brush l3and the corresponding contacting plate such as 21, the rotating membercould be the brush, the nonrotating member being the plate. Instead of asingle brush, as shown, two or more may be used, if desired.

I claim:

1. In an electric railway vehicle having a frame and rotating axles tosupport said frame with each of said axles having two ends, a device forcurrent transmission between said frame and one of the ends of saidaxles, said device comprising:

a nonrotating contacting member carried by said frame substantially infront of said one end of said one of said axles;

a rotating contacting member engaging said nonrotating contactingmember;

means on said frame to rotatably support said rotating contactingmember;

spring means to resiliently urge said nonrotatin g contacting member andsaid rotating contacting member against each other to maintain same inpermanent electric sliding contact;

universal coupling means between said rotating contacting member andsaid one end of said one of said axles to cause said rotating contactingmember to rotate in unison therewith in spite of the displacements ofsaid one of said axles with respect to said frame;

and flexible conductor means to electrically connect said rotatingcontact member with said one end of said one of said axles.

2. in a current-transmitting device as claimed in claim 1, said rotatingmember including a shaft having a first and a second end, and a flatcontacting plate carried by said first end of said shaft, saidnonrotating member being formed of a support and of at least one brushslidably carried by said support to engage said contacting plate withsaid spring means acting on said brush to apply same against said plate,said device further comprising means to prevent said brush from rotatingtogether with said plate, and said universal coupling means acting onthe second end of said shaft.

3. in a current-transmitting device as claimed in claim 2, a flexibleconductor means between said brush and said support.

4. In a current-transmitting device as claimed in claim 2, said one ofsaid axles having a mean position with respect to said frame, said shaftbeing substantially coaxial to a said mean position, and said universalcoupling means comprising a driving member secured to said one end ofsaid one of said axles, said driving member being formed with a guidingslot radially disposed with respect to said one of said axles; a crankarm radially secured to said second end of said shaft, said crank armhaving an outer end; and a crankpin carried by the outer end of saidcrank arm, said crankpin being slidably engaged into said slot.

5. In a current-transmitting device as claimedin claim 2, said frameincluding an open-ended sleeve in front of said one end of said one ofsaid axles, with an outer end remote from said one end of said one ofsaid axle and an inner end adjacent to said one end, said support ofsaid nonrotating contacting member being removable secured to the outerend of said sleeve, and said means to rotatably support said rotatingcontacting member being comprised of bearing means carried by saidsupport and in which the shaft of said rotating contacting member ismounted.

6. in a current-transmitting device as claimed in claim 1:

said frame including an open-ended sleeve disposed in front of said oneend of said one of said axles said sleeve having an outer end remotefrom said one end of said one of said axles and an inner end adjacent tosaid one end;

said device further comprising a tubular body disposed within saidsleeve, said body having a first open end removably secured to the outerend of said sleeve and a second end;

said means to rotatably support said rotating contacting member beingcomprised of bearing means carried by the second end of said tubularbody;

said rotating contacting member including a shaft mounted in saidbearing means and a contacting end plate supported by said shaft withinsaid tubular body;

said nonrotating contacting means including a brush applied against saidcontacting end plate within said tubular body, a tail carrying saidbrush, said tail having a noncircular cross section, and a removablecover closing the first end of said tubular body, said cover beingformed with an axial perforation having a cross section complementary ofthe cross section of said tail and through which said tail is slidablyguided;

said spring means being inserted between said cover and said brush;

and said device also comprising flexible conductor means between saidtail and said frame,

7. In a current-carrying device as claimed in claim 1, said spring meansbeing disposed between said rotating contacting member and said one endof said one of said axles so as to form said universal coupling means.

1. In an electric railway vehicle having a frame and rotating axles tosupport said frame with each of said axles having two ends, a device forcurrent transmission between said frame and one of the ends of saidaxles, said device comprising: a nonrotating contacting member carriedby said frame substantially in front of said one end of said one of saidaxles; a rotating contacting member engaging said nonrotating contactingmember; means on said frame to rotatably support said rotatingcontacting member; spring means to resiliently urge said nonrotatingcontacting member and said rotating contacting member against each otherto maintain same in permanent electric sliding contact; universalcoupling means between said rotating contacting member and said one endof said one of said axles to cause said rotating contacting member torotate in unison therewith in spite of the displacements of said one ofsaid axles with respect to said frame; and flexible conductor means toelectrically connect said rotating contact member with said one end ofsaid one of said axles.
 2. In a current-transmitting device as claimedin claim 1, said rotating member including a shaft having a first and asecond end, and a flat contacting plate carried by said first end ofsaid shaft, said nonrotating member being formed of a support and of atleast one brush slidably carried by said support to engage saidcontacting plate with said spring means acting on said brush to applysame against said plate, said device further comprising means to preventsaid brush from rotating together with said plate, and said universalcoupling means acting on the second end of said shaft.
 3. In acurrent-transmitting device as claimed in claim 2, flexible conductormeans between said brush and said support.
 4. In a current-transmittingdevice as claimed in claim 2, said one of said axles having a meanposition with respect to said frame, said shaft being substantiallycoaxial to said mean position, and said universal coupling meanscomprising a driving member secured to said one end of said one of saidaxles, said driving member being formed with a guiding slot radiallydisposed with respect to said one of said axles; a crank arm radiallysecured to said second end of said shaft, said crank arm having an outerend; and a crankpin carried by the outer end of said crank arm, saidcrankpin being slidably engaged into said slot.
 5. In acurrent-transmitting device as claimed in claim 2, said frame includingan open-ended sleeve in front of said one end of said one of said axles,with an outer end remote from said one end of said one of said axle andan inner end adjacent to said one end, said support of said nonrotatingcontacting member being removably secured to the outer end of saidsleeve, and said means to rotatably support said rotating contactingmember being comprised of bearing means carried by said support and inwhich the shaft of said rotating contacting member is mounted.
 6. In acurrent-transmitting device as claimed in claim 1: said frame includingan open-ended sleeve disposed in front of said one end of said one ofsaid axles said sleeve having an outeR end remote from said one end ofsaid one of said axles and an inner end adjacent to said one end; saiddevice further comprising a tubular body disposed within said sleeve,said body having a first open end removably secured to the outer end ofsaid sleeve and a second end; said means to rotatably support saidrotating contacting member being comprised of bearing means carried bythe second end of said tubular body; said rotating contacting memberincluding a shaft mounted in said bearing means and a contacting endplate supported by said shaft within said tubular body; said nonrotatingcontacting means including a brush applied against said contacting endplate within said tubular body, a tail carrying said brush, said tailhaving a noncircular cross section, and a removable cover closing thefirst end of said tubular body, said cover being formed with an axialperforation having a cross section complementary of the cross section ofsaid tail and through which said tail is slidably guided; said springmeans being inserted between said cover and said brush; and said devicealso comprising flexible conductor means between said tail and saidframe.
 7. In a current-carrying device as claimed in claim 1, saidspring means being disposed between said rotating contacting member andsaid one end of said one of said axles so as to form said universalcoupling means.